FR2727473A1 - Manual pump for perfume sprayer - Google Patents

Abstract

The manual pump (2) consists of an entry valve (42,411) and a discharge valve (121,41) each one having a valve seat. It is characterised in that the said pump chamber (2) is made up by a unit in a supple material (1) which defines an internal variable volume depending on the state of its deformation. The supple chamber has an outside edge (121) which pushes against an element of the discharge valve (41) in a manner to create an elastically sealing contact arranged to break when a sufficiently high enough pressure is exerted onto the supple unit.

Description

 The present invention relates to a manual pump for dispensing fluid and more especially liquid products such as perfumes, lotions, solutions, etc.

More particularly, this pump is intended to be mounted on very small tanks of the order of a few milliliters, for example perfume samples
Conventionally, any manual pump comprises a chamber provided with an inlet valve in communication with a product reservoir and an outlet valve in communication with the outside, in general through a spray nozzle. The pump chamber is usually delimited by the internal walls of a pump body and a piston mounted to slide in said pump body. The room is therefore defined by at least two elements. there are many types of inlet valve operating for example with a washer or a ball or even by fitting a skirt on a protruding sleeve in a room. As for the outlet valves, the diversity is no less great. Be that as it may, the total number of components of a conventional pump, including seals and balls, is often around ten and sometimes even exceeds it.

 In the case of the particular application to distributors of small sizes, it is necessary to use pumps of proportional sizes. A miniaturization of the conventional pump elements mentioned above seems difficult, but above all very expensive. Another alternative capable of meeting the requirements linked to miniaturization is the reduction of the total number of component parts of the pump.

However, this reduction poses problems, since the pump must fulfill the same functions as a conventional pump, but with fewer parts. This means that certain parts will have to fulfill several functions. An example of a multifunctional part is the bellows which acts as a pump and piston chamber in many known distributors.

 One of the aims of the present invention is to produce a distributor of reduced size incorporating a minimum number of constituent parts while ensuring the vital functions of a conventional pump. The present invention proposes to reduce this number to less than five or even three, including the product reservoir.

 Another object of the present invention is to provide a dispenser incorporating no metal part, and preferably entirely made up of compatible plastics so that the pump can be recyclable without the need for disassembly to extract certain parts.

 Another problem which the invention seeks to solve stems from the fact that the tanks on which the pump of the invention is mounted have a neck diameter as well as an extremely small volume. It is therefore preferable that the pump does not enter the tank while occupying part of the volume therein, and yet does not protrude disproportionately and unsightly above the tank. This is why the pump must be particularly compact in the height direction.

 To do this, the present invention relates to a manual pump comprising a pump chamber, an inlet valve and an outlet valve each having a valve seat, characterized in that said pump chamber is constituted by a member in flexible material defining a variable internal volume as a function of its deformation state, said flexible member having a peripheral edge in abutment against an outlet valve element so as to create a tight elastic contact adapted to break when sufficient pressure is exerted on said flexible member. The flexible member thus fulfills four distinct functions: pump chamber, piston, spring and outlet valve.

 According to a first embodiment, said flexible material member comprises an envelope extending in the shape of a bell, said envelope having a rigid free end portion forming said peripheral edge, said rigid peripheral edge having an annular contact with a flexible element. sealed adapted to undo by flexing of said flexible element, when sufficient pressure is exerted on said chamber, so as to constitute the outlet valve for the pump fluid.

Advantageously, said flexible element is a washer fixedly held in its center and receiving on its free external periphery the rigid peripheral edge. This characteristic consisting in using a flexible washer as an outlet valve member has already been the subject of a French patent application nO. 93 15249.

 According to another embodiment, said flexible material member comprises an envelope extending in the shape of a bell, said envelope having a flexible free end portion forming said peripheral edge, said flexible peripheral edge having with a fixed structural element of the pump a sealed annular contact adapted to undo by deflection of said flexible peripheral edge when sufficient pressure is exerted on said chamber, so as to constitute the outlet valve for the pump fluid. Advantageously, the inlet valve seats and outlet are formed in one piece, and the flexible free end portion of the envelope forms an annular tightening directed inwards, said fixed structural element being an outer annular surface of a central sleeve projecting in the pump chamber, said sleeve extending by a dip tube internally forming said seat inlet valve, and externally said outlet valve seat. Preferably, the inlet and outlet valve seats and the support seat are formed in one piece with a fluid reservoir. The distributor is then made up only of these three parts.

 According to a characteristic common to the two abovementioned embodiments, the flexible envelope near its maximum diameter is received in a fixed support seat adapted to withstand the pressure stresses exerted on the deformable pump chamber.

 According to another particularly advantageous characteristic capable of being implemented in the two abovementioned embodiments, said flexible material member comprises a central boss around which said envelope extends circumferentially. Advantageously, said central boss of said flexible member is constituted by a deformable axial central needle having a lower end adapted to engage on said seat of said inlet valve by obstructing it when sufficient pressure is exerted on said pump chamber in the direction of the axis of the needle, said needle having an upper end to which is connected a flexible envelope forming with said needle a single piece. Thus, the flexible member fulfills a fifth function by acting as a valve member Entrance. As a variant or in combination, a central sleeve projects into the pump chamber, said central boss of said flexible member being constituted by an axial central needle at least partially engaged in said central sleeve, for guiding said member of flexible material in the axial direction of the needle.

 According to another embodiment of the needle, the latter forms a flexible frustoconical part whose lower end is substantially annular and adapted to come into tight contact with a wall forming an inlet valve seat.

Advantageously, the inlet valve wall is formed by a washer whose center is connected to a dip tube and the outer periphery is in sealed contact with the peripheral edge, the washer and the dip tube being in one piece. Preferably, the flexible envelope forms with the frustoconical needle a central bitronconic axial part, in the form of a diabolo, surrounded circumferentially by an external part of complementary binonconic shape so as to produce a meridian revolution pump chamber in the form of a chevron allowing , when actuating the pump, reduce the pump chamber to almost zero volume.

 According to other characteristics of the invention, the pump is received on a fluid reservoir by means of a seal, said seal having an unstressed part between the pump and the reservoir, said unstressed part making an ornament of the air intake valve in communication with the outside via an air intake channel formed in the pump. On the other hand, the flexible member incorporates a pusher to act in compression on the pump chamber.

Advantageously, the pusher incorporated in the flexible member has an axial central recess to increase the elastic properties of the flexible member. As a variant, the flexible member has a housing receiving a centering lug secured to a pusher.

Advantageously, the inlet valve is in communication with a product tank via a dip tube, only the dip tube entering the tank.

 The present invention will now be described more fully with reference to the accompanying drawings which give, by way of nonlimiting examples, several embodiments of the invention.

In the drawings:
- Figure I is a partially truncated cross-sectional view of a
complete distributor produced in accordance with the present invention,
- Figure 2 is a cross-sectional view of a design distributor
somewhat similar to that of figure 1,
- Figure 3 is a cross-sectional view of another embodiment
a dispenser according to the invention,
FIG. 4 is an alternative embodiment of the dispenser of FIG. I, and
- Figure 5 is a cross-sectional view of another embodiment of
the invention.

 Throughout the following description, the same elements fulfilling the metes functions will be designated by the same reference numerals, unless otherwise stated. The dispenser shown in Figure I consists of only five parts, namely, a tank body 3, a tank bottom 6, a dip tube 4, a nozzle 5 and a member made of flexible material 1 One of the most advantageous of the invention resides in this flexible member 1 which has a complex structure ensuring several vital functions for the operation of the pump integrated in the dispenser.

Said member is formed with a central needle 1 1 which is deformable by compression in the axial direction of the pump. At the upper end of this needle 11 is connected a flexible envelope 12 which extends circumferentially around said needle. The connection between the needle and the envelope is reinforced and forms a pusher for actuating the dispenser. The flexible member is essentially held in place by the reception of an annular reinforcement 122 of the envelope in a support seat 31 formed integrally with the tank body 3. The tank body 3 also forms in its upper part a reinforcement collar 34 which extends annularly upwards. The collar 34 is engaged with its internal wall with the flexible envelope and therefore also contributes to its seating on the support seat 31 which constitutes in a way the base of the collar 34. The collar incorporates an air intake channel 33 which communicates the interior of the tank with the exterior to allow the replacement of the volume of product pumped by air. The flange is also provided with a housing for receiving the spray nozzle or nozzle 5 which communicates with the chamber 2 via an outlet channel 32. Said outlet channel 32 extends annularly around an axial central sleeve 41 which projects into the pump chamber 2.

According to the invention, the flexible envelope 12 is provided with a peripheral edge 121 beyond the annular reinforcement 122 which extends towards the needle 11 thereby forming a constriction. The end of the peripheral edge 121 is in contact with the outer wall of said central sleeve 41. The peripheral edge 121 of the casing 11 is flexible and liable to deform under the effect of the pressure prevailing in the pump chamber 2 during of its actuation. The contact between the peripheral edge 121 and the sleeve is a leaktight contact capable of breaking apart. The external wall of the sleeve 41 therefore constitutes a valve seat for this peripheral edge 121 which acts as a valve member.
To complete the seal, the end 121 of the casing 12 rests against an annular shoulder formed by the sleeve 41 on its outer face. Preferably, the end 121 of the envelope will undergo a prestress by pressing against this shoulder so as to create a certain precompression in the chamber at the time of actuation of the pump.

 On the other hand, the needle It is partially engaged in said sleeve 41, even when the pump is at rest. This guarantees good maintenance in the center line of the needle and thereby of the flexible member 1 during its crushing by pressing on the integrated pusher 13.

 The needle 1 1 is therefore slidably mounted in the sleeve 41, without however creating a sealed contact. Indeed, the needle is provided with vertical grooves 112 which allow the passage of the fluid from the reservoir into the chamber 2. It is only during the crushing of the chamber that the lower end 1 of the needle comes into tight contact with a surface formed by a part of the internal wall 42 of the sleeve. In the embodiment described, this wall contact part 42 of tight contact has a frustoconical shape and constitutes a connection with the dip tube 4 which extends inside the tank. As can be seen in Figure 1, the sleeve 41 and the dip tube 4 constitute a single piece inserted in an orifice formed in the tank body 3. It is also possible to manufacture the dip tube 4 and its sleeve 41 in one piece with the reservoir body 3. The pump would then only be made up of four parts, including the bottom 6 of the reservoir.

 The sleeve 41 in collaboration with the needle 11 forms a means for holding in the axis when the needle moves by crushing the chamber and an inlet valve by contact with the end 111 of the needle and the frustoconical surface 42 which acts as an inlet valve seat.

 To further improve the axial stability of the chamber when it is crushed downwards, the flexible member 1 forms at its pusher a peripheral skirt 131 whose internal surface is in sliding contact with the external surface of the flange of reinforcement 34. The contact surface defines a guide cylinder indented at 132 to allow the nozzle 5 to pass.

 To improve the deformability properties of the flexible member, the incorporated pusher 13 is provided with a central recess 133 which has the consequence of reducing the wall thickness of the envelope at the level of connection to the axial needle 11. This allows , during the crushing of the flexible member, to allow the flexible envelope 12 to sink more deeply with the needle returning into the recess 133.

 Thus, when the pump is actuated by exerting pressure on the pusher 13 integrated into the flexible member 1, the needle 1 1 begins by moving downwards until it comes into contact with the seat surface 42. At this time, the chamber 2 is isolated from the tank. By continuing to press the pusher 13, the needle is deformed axially and allows a reduction in the volume of the chamber. This reduction in volume is accompanied by a leak of the product initially contained in the chamber by an annular passage created by the deformation of the peripheral edge 121 of the envelope away from the sleeve 41. The product expelled from the chamber 2 arrives in the channel of annular outlet 32, then passes into the swirl chamber of the nozzle to finally be expelled in vaporized form. As soon as the pressure on the pusher 13 is released, the needle resumes its initial form of rest, then breaks its contact with the surface 42. Product coming from the reservoir is then sucked into the chamber through the dip tube 4. L Aspiration continues until the chamber has returned to its initial form of rest.

 During compression of the chamber, the only part of the flexible member to remain static is the annular reinforcement 122 which takes up a large part of the applied pressure force. The walls of the flexible envelope 12 also deform during the crushing of the chamber by necessarily moving towards the interior of the chamber since the envelope 12 is surrounded externally by the reinforcing collar 12 which thus promotes the reduction of chamber volume.

 Of course, with the embodiment described, it is hardly possible to expel all of the product contained in the chamber, but only one part may be sufficient to constitute a dose. The main advantage lies in the compactness of the pump functions which are fulfilled only by two parts, namely the flexible member 1 and the sleeve 41. These act as chambers, pistons, inlet and outlet valves. In addition, these two parts are received on or in another one-piece part which incorporates the tank. The few component parts of this pump make them an easy assembly assembly: the general concept of fixing being the fitting. This is particularly advantageous when you know the actual size of the parts. For example, the height of the pump outside the dip tube does not exceed one centimeter for a diameter of the order of one centimeter.

 Another advantage arising from the design of the pump according to the invention lies in the fact that the nozzle can be placed at the same level as the chamber. This practically reduces the total height of the pump to the height of the flexible member 1.

 This is not the case with the embodiment of FIG. 2 in which the nozzle 5 is located below the chamber and communicates with it via an annular channel 32 similar to that of FIG. 1. In this embodiment, only the characteristics different from that of FIG. I will be described in detail. The internal room fox is almost identical. However, the pusher 13, in FIG. 2, is not an integral part of the flexible member 1, but is connected thereto by means of a central lug 134 formed with a lower end in dovetail received in a corresponding housing in the flexible member 1. Another feature of this second embodiment is the use of a ball 7 as an inlet valve member. In this case, the needle 11 no longer serves as a guidance for the proper maintenance in the axis of the flexible member during its crushing. The ball acts as a stop for the lower end 111 of the needle 11, which further improves the sealed contact of the ball on the seat surface 42.

 It can also be noted that the part receiving the flexible member 1 is entirely formed with the sleeve 41 and the dip tube 4, but does not form the reservoir.

This pump is intended to be mounted on a separate tank. For this, the pump is provided on the internal surface of the fixing ring 35 with a latching cord 36 intended to be received in a groove formed in the neck of the reservoir.

 The pump of Figure 2 consists of five parts, including the ball and not counting the tank.

 The flexible member 1 of the pump of Figure 3 is of a different geometry, specially adapted to reduce the dead spaces inside the chamber when the latter is completely crushed. The flexible member 1, like those of the previous embodiments of Figures 1 and 2 has an axial symmetry of revolution coinciding with the vertical axis of the pump, the symmetry of revolution not being observed only at the level of the nozzle 5 to allow its passage. However, in the case of the pump of FIG. 3, the central needle 11 is in the form of a frustoconical element 113 similar to a suction cup from the upper end of which the flexible envelope extends so as to define a bitronconical part 113, 123 with an X-shaped section.

The envelope 12 then extends circumferentially around this bitronconical part 113, 123 with a complementary bitronconic part 124 so as to create a cylindrical pump chamber volume of meridian revolution substantially in the form of a diabolo. The annular reinforcement 122 is at the same level as the lower end of the needle 111 and is received in a support seat 31 similar to those of FIGS. 1 and 2. The end part of the flexible envelope 12 is also received in a reinforcement flange 34 which is an integral part of the fixing ring 35. The end 121 of the casing 12 is at the same level as the reinforcement 122 and is in sealed contact with the peripheral edge 41 of a flexible washer 412 .

In this embodiment. the end 121 of the envelope is rigid and undeformable due to its holding on the support seat 31 and its thickness at this location
The end 121 here acts as the outlet valve seat and not as a valve member, as in the previous embodiments. It is the deformation of the washer under the effect of the pressure which makes it possible to create an outlet passage for the fluid expelled from the chamber.

 On the other hand, the flexible washer 412 also serves as an inlet valve seat on its central annular surface 42 by sealed sliding contact with the lower end 111 of the frustoconical needle 11. When the pump is at rest, the frustoconical needle is not in contact with the washer 412 and the chamber therefore communicates with the reservoir.

When the pump is actuated, the annular end 111 of the needle comes into contact with the annular planar surface 42 of the flexible washer 412 and thus isolates the chamber from the reservoir. By continuing to press the pusher 13 integrated into the member 1, the sealed annular contact between the needle 11 and the washer 412 increases in diameter by deformation of the lower end of the needle towards the outside. This annular contact also promotes breakage of the contact between the outer edge 41 of the washer and the end 121 of the envelope.

 In some cases, depending on the material used to make the flexible washer 412, this arrangement giving the washer a dual function may be preferred, especially since it is easier to determine the deflection threshold of a washer than from the flexible edge of the envelope. Thus, the use of a washer as an outlet valve member seems to be a preferred embodiment. The inlet valve seat can be formed with another surface independent of the opening of the outlet valve. The implementation of a flexible washer can also be applied to the embodiments of FIGS. 2 simply by eliminating the flexible annular tightening forming the end 121 of the envelope 12 and by placing a flexible washer centered on the sleeve 41.

 To actuate the pump, press the pusher 13 integrated into the member 1.

The complementary bitronconical part 124 begins to flex inward at the level of the fold of the rafter. Shortly thereafter, the annular end 111 of the needle comes into contact with the surface 42 and the washer 412 and isolates the chamber from the reservoir. From this moment, the annular contact of the needle and the washer will move away radially until reaching a maximum during the total crushing of the chamber. At the same time,
The envelope 12 on its bitronconical part 124 flexes inwards. The pressurized product initially contained in the chamber flows through the passage created by the deflection of the washer 412 which has then broken its peripheral annular contact with the end 121 of the envelope 12.

 The flexing of the flexible member inwards makes it possible to reduce the volume of the chamber to an almost zero value. In addition, the deformation of the needle towards the outside makes it possible to further reduce the dead volumes inside the chamber when it is completely crushed.

 It can be noted that the washer forms a single piece with the dip tube 4 which is inserted into an orifice made in the fixing ring 135. The pump of FIG. 3 is thus made up of only four separate pieces.

 Referring now to FIG. 4, a pump is shown having a geometry substantially similar to that of FIG. 1 There are, however, two structural differences at the level of the needle II and the air intake channel 33.

 Indeed, the needle 11 is here shorter than that of Figure I and have vertical grooves 112 only over part of its height. Thus, the needle stroke in the sleeve 41 is greater, which makes it possible to reduce the volume of the chamber all the more, no longer by deformation of the needle, but simply by its vertical displacement, in a manner analogous to a conventional piston. . however, here, the chamber is not located below or above the piston, but surrounds it circumferentially. the inlet valve is closed as soon as the needle is engaged in the sleeve sufficiently deep so that the non-grooved part of the needle comes into contact with a sealing bead 411 formed near the end of the internal wall of the sleeve 41. The pump chamber is then isolated from the reservoir and will remain so until the non-grooved part rises beyond the cord 411. The frustoconical surface 42 then only feels as a limit stop.

 The second feature of this embodiment comes from the air intake system. Like the pump of FIG. 1, an air return channel 33 is formed in the reinforcement collar 84. This channel 33 first extends vertically in the collar 34, but also defines a groove 331 which extends radially up to the dip tube 4. In the case of FIG. 4, the pump is intended to be mounted on the neck of a tank. According to the invention. the seal 8 interposed between the pump and the neck of the reservoir covers the groove 331 and extends radially inward until it contacts the dip tube 4. The pump, at the level of the inlet of the tube - plunger in the tank forms a conical reinforcement 37 to which the seal 8 is applied. By its conical shape, the reinforcement 37 biases a central portion 81 towards the bottom of the seal which therefore exerts a certain pressure against the dip tube, thereby sealing off the air intake groove 331. When the reservoir is in place in the ring 35, the end of the neck is not in contact with the part 81 of the seal 8 which thus remains unstressed by crushing. During the operation of the pump, product is sucked out of the tank, which creates a vacuum in the tank. Air can then enter the reservoir through the channel 33 and the groove 331 after having slightly bent the central particle 81 of the seal 8 at the level of the groove 331. It will therefore be necessary for the vacuum inside the reservoir is large enough to bend the central part 81 of the joint 8. Nevertheless, the product inside the tank, thanks to this arrangement, is not in direct relation with the outside air via the simple channel 33, which could fan or oxidize it.

 Referring now to Figure 5, there is shown a pump incorporating a flexible material member according to the invention devoid of axial needle. The inlet valve member is a ball 7 pressed against a seat surface 42 when the chamber 2 is pressurized. As in the embodiment of FIG. 3, the plunger rod 4 is formed in a single piece with a flexible washer which acts as an outlet valve co-operation with the rigid peripheral edge 121 of the flexible member 1. The flexible envelope 12 has a general shape similar to that of a bellows with a supernatural fold of a dome forming the pusher 13. The flexible envelope is kept close to its peripheral edge 121 in its seat 31. When the chamber 2 is crushed, the single fold, forming an annular tightening, is pronounced even more so that the dome part 13 comes into contact with the part 122 received in the seat 31.

 The pump here consists of five parts, including the ball.

Claims (19)

Claims  1.- Manual pump comprising a pump chamber (2), an inlet valve (11, 42, 411) and an outlet valve (12I.41) each having a valve seat, characterized in that said pump chamber (2) is constituted by a flexible material member (1) defining a variable internal volume as a function of its deformation state, said flexible member having a peripheral edge (121) resting against an outlet valve element (41) of so as to create a tight elastic contact suitable for romprc when sufficient pressure is exerted on said flexible member.  2. A manual pump according to claim I, wherein said flexible material member (I) comprises an envelope (12) extending in the shape of a bell, said envelope having a rigid free end part (121) forming said edge. peripheral, said rigid peripheral edge (121) having with a flexible element (412) a sealed annular contact adapted to come apart by bending of said flexible element (412), when sufficient pressure is exerted on said chamber (2), so to constitute the outlet valve for the pump fluid.  3. A manual pump according to claim 2, wherein said flexible element is a washer (412) fixedly held in its center and receiving on its free external periphery (41) the rigid peripheral edge (121).  4. A manual pump according to claim 1, in which said flexible material member (1) comprises an envelope (12) extending in the shape of a bell, said envelope (12) having a flexible free end part (121). forming said peripheral edge, said flexible peripheral edge (121) having, with a fixed structural element (41) of the pump, a sealed annular contact adapted to come loose by bending of said flexible peripheral edge (13,1) when sufficient pressure is exerted on said chamber (2), so as to constitute the outlet valve for the pump fluid.  5. A manual pump according to any one of the preceding claims, in which the flexible envelope (12) near its maximum diameter is received in a fixed support seat (31) adapted to withstand the pressure stresses exerted on the deformable pump chamber (2).  6.- Manual pump according to claims 1 or 4, wherein the inlet valve seats (41) and outlet (42) are formed in one piece.  7. A manual pump according to claim 6, in which the flexible free end portion (121) of the casing (12) forms an annular constriction directed inwards, said fixed structural element being an outer annular surface d '' a central sleeve (41) projecting into the pump chamber (2), said sleeve (41) extending by a dip tube internally forming said inlet valve seat (42), and externally said seat (41) outlet valve.  8.- Manual pump according to claim 5, wherein the inlet valve seats (41) and outlet (42) and the support seat (31) are formed in one piece with a fluid reservoir (3 ).  9. A manual pump according to any one of claims 2 to 8, wherein said flexible material member (1) comprises a central boss (11) around which said casing (12) extends circumferentially.  10.- Manual pump according to claim 9, wherein said central boss of said flexible member is constituted by a deformable axial central needle (11) having a lower end (111) adapted to engage on said seat of said inlet valve ( 42) by obstructing it when sufficient pressure is exerted on said pump chamber (2) in the direction of the axis of the needle (11), said needle (11) having an upper end to which a flexible casing is connected (12) forming with said needle a single piece (1).  11. A manual pump according to claim 9 or claim 10, in which a central sleeve (41) projects into the pump chamber (2), said central boss (11) of said flexible member being constituted by an axial center needle ( 11) at least partially engaged in said central sleeve (41), to guide said member in flexible maceration in the axial direction of the needle.  12. A manual pump according to claim 10, in which the needle (11) forms a flexible frustoconical part (113) whose lower end (111) is substantially annular and adapted to come into tight contact with a wall (42) forming inlet valve seat.  13. A manual pump according to claim 12, in which the wall (42) of the inlet valve is formed by a washer (412) the center of which is connected to a dip tube (4) at the outer periphery (42). is in sealed contact with the peripheral edge (121), the washer (412) and the dip tube (4) being in one piece.  14.- A manual pump according to claim 12 or claim 13, in which the flexible envelope (12) forms with the frustoconical needle (113) a central bitronconical axial part (113, 123) circumferentially surrounded by an external part (124). of complementary bitronconical shape so as to produce a chevron-shaped meridian revolution pump chamber making it possible, during the pumping of the pump, to reduce the pump chamber to an almost bare volume  15.- Manual pump according to any one of the preceding claims, in which the pump is received on a fluid reservoir (3) by means of a seal.  seal (8), said seal (8) having an unstressed portion (81) between the pump and  the tank, said unconstrained part (81) providing an intake valve member for  return air in communication with the outside via a return channel  air (33) formed in the pump.  16.- Manual pump according to any one of the preceding claims, in  which the flexible member (1) incorporates a pusher (13) to a5ir in compression on the  pump chamber (2).  17.- Manual pump according to claim 16, wherein the pusher (13)  incorporated in the flexible member (1) has a central axial recess (13) to increase  the elastic properties of the flexible member.  18.- Manual pump according to any one of the preceding claims, in  which the flexible member (1) has a housing receiving a centering lug (134)  integral with a pusher (13).  19.- Manual pump according to any one of the preceding claims, in  which the inlet valve (42) is in communication with a product reservoir via a dip tube (4), only the dip tube (4) entering the reservoir.